Fuel valve with annular seat



Jlc/b d l s Jh,

i' Patented sept. 1, 1931 UNITED STATES PA'I'ENrl OFFICE OVE PETERSEN', 0F HELLERUP, NEAR COPENEAGEN', :DENMARKr FUEL VALVE WITH ANNULAB SEAT Application led August 25, 1927, Serial No. 215,484, and in Denmark .Tilly 9, 1927.

ed by a fuel pump driven by the engine, and

without spraying by compressed air.

"t n fuel valves for this kind of engines the fuel is injected through a passage provided in an injecting nozzle, and generally the ar- 1a rangement is such that the valve opens this passage or channel when the pressure of the fuel oil reaches a suflicient height, the pressure acting on an annular area consisting in the difference between the cross sectional 15, area ofthe valve spindle and the valve seat absolutely tiglht against its sp erical or conical in shape.

i area and thereby overcoming the spring tension or the like which normally keeps the valve c1osed. .On account of the height of the pressure it is ditlicult to make the valve at and also to maintain tig tness during t e working of the engine, as the valve gradually will become damaged o n account of the fact that the spring causesthe valve spindle to strike the seat with considerable force, so that the seat has to suddenly stop the movement of the spindle and to receive the total amount of ener contained therein.

Accor ing to the present invention the said drawback is overcome by providing the injecting nozzle with a drilled or boredhole, l

for instance of conical sha e or the like, while the s indle is provided with a corresponding rilled or turned hole. In this way the end surface of the spindle becomes shaped as an annular valve seat which corresponds with the annular seat of the inject-4 in nozzle, which latterv seat may be Hat, The said drilled or bored holes or recesses are of advantage in that the valve spindle lift. may be small, namely as a .result firstly of the recess in the valve seat, the inner diameter of said recess being essentially reater than the diameter of the usual centra passage in the nozzle. The cross sectional passage aea of a valve may namely, as will be known, be calculated as the product ofthe peripheral length ofthe inner bounding circle of the valve seat and the lift of the valve. Thus' a sufficiently great passage area may be obtained even if the lift is only small, when the inner circle islarge. Secondly the recess in the valvespindle forms better hydraulic properties for the flow of luid, so that said latter recess also contributes to obtain the advantages of a small lift'. Among such advantages may be mentioned that the employment of a lighter spring is made possible. A spring which shall allow a large movement must, namely, have a great number of turns or coils, whereas a spring which shall work with a small movement only needs a few coils. If the said recesses did not exist a reduction of the lift of the valve spindle would not be possible even if the outer diameter of the valve seat and the diameter of the spindle lwere great, because the material in the end surface of the spindle and within the valve seat, would namel restrict the cross sectional passage area. suciently great bearing area for the annular valve seat may easily be obtained,y namely by making the outer diameter of the spindle and the valve seat suitably greater than the inner diameter of the recesses, and at the same time the differential area of the valve spindleto be affected by the fuel oil pressure openin the valve is suitably made small, so that t ereby further the emplo ment of a small and light spring is mad possible.

The invention is illustrated in the drawin s, in which ig. 1 shows a longitudinal sectional view of a constructional form of a fuel valve according to the invention, and

Fig. 2 part of another constructional form, in longitudinal sectional view.

In Fig. 1 the reference character w indicates the valve spindle, b the injecting nozzle and c a nut servin to clamp the nozzle to the valve housing The injecting nozzle is provided with a spherically shaped end surface la at bottom, which cooperates with a corresponding surface on the nut a. The valve housing d 1s provided with an adjustable stop e at top, which serves to restrict 'the lift of the valve spindle a. A spring ftends to close the valve spindle a,

the said spring f transmitting its tension through the member g. The lower end of the bottom portion of the valve spindle a, which bottom ortion al has a reduced diameter, is shaped according to the invention, as a conical annular seat 7' surrounding a conical or cup-shaped depression or drilled hole k, and the injecting nozzle b, which is provided with a centrally arranged hole mi, is provided with a similar drilled hole Z. The fuel oil is admitted through the connection n, the channel or passage o and the annular space p surrounding the bottom portion al of the valve spindle.

The mechanism now acts in the following way:

When the pressure on the fuel oil in the space p has reached a certain height, this pressure will lift the spindle m by its action on the annular differential area al, of the valve spindle. When the spindle is lifted awayfrom its seat the fuel becomes capable of acting o'n the whole cross sectional area of the spindle. Accordingly the lifting of the lspindle towards the stop will be very rapid, while its stroke against the stop will only be with small force because of the slight lift. Correspondin ly the closing movement will be very rapid ecause of the slight lift and still without being accompanied by a hard stroke, because the energy is only small.

In the constructional form illustrated in Fig. 2, in which corresponding parts are indicated by the same reference characters as in Fig. 1, the spindle is provided at its bottom end with a conically turned portion g or the like, and the valve seat of the injecting nozzle b is similarly restricted by a surroundin conically or similarly shaped vsurface. T e purpose hereof is to obtain that the surfaces between which the edges of the valve vseats (on the spindle as well as on the injecting nozzle) are situated form the largest possible angles with each other, preferably obtuse angles, which serves to make the said edges last better in that they are not so easily broken olf during the working of the engine. In this constructional form the face h of the injecting nozzle b is made iiat. The valve housing is at its lower end provided with a cylindrically turned portion s of a diameter corresponding to that of the injecting nozzle, and the nut a has a correspending drilled hole with the same diameter. It is possible by this means to centre the injecting nozzle in its clamped position with an accuracy which is greater than that` obtained by means of screw thread.

The term upsetting used in connection with the making of all edges with obtuse angles means the process which takes place in the material when it is exposed to violent blows and pushes, whereby the material flows out.

The seat j may, as shown in the drawings,

trally arranged recesslso as to provide an be conical of shape, or it may be fiat or sphericallysha ed. The surface area of the seat is prefera l made of a size a little greater than hal the cross sectional area of the valve spindle. i

The invention is not bound to comprise only the constructional forms above described and set forth, but may be carried out in several different ways without thereby departing from the principles of the invention.

I claim:

1. Fuel valve for internal combustion engines of the kind in which the fuel is injected directly into the cylinder by means of pump pressure which in itself also serves to move the valve spindle away from the valve seat, characterized in that the end of the valve spindle is provided with a centrally arranged recess, the surface of which makes an angle with Lthe annular end face of -the valve spindle greater than and the seat cooperating with the valve spindle being provided with a corresponding cenannular valve seat w ich cooperates with the annular end face of the valve spindle when the valve is closed.

2. An improved fuel valve `for internal combustion engines of the type operating with direct injection of fuel, comprising a. housing, a valve spindle movable longitudinally in the housing and rovided on its inner annular end face wit a centrally arranged recess the surface of which makes an angle with the end face greater than 90, and a member arranged at the end of the housing for cooperating with the spindle and provided wlth a correspondingly arranged central recess so as to form a valve seat which cooperates with the annular end face of the spindle when the valve is closed.

3. An improved fuel valve for internal combustion engines of the type operating with direct injection of fuel, comprising a housing, a valve spindle movable longitudinally in the housing and provided on its inner annular end face with a centrally arranged recess the surface of which makes an angle with the end face greater than 90,

and a seat plug secured to the inner end of the housing cooperating with the valve spindle and provided on its inner end face with` a correspondingly arranged central recess so as to form a valve seat which cooperates with the annular end face of the spindle when the valve is closed.

4. A fuel valve as claimed in claim 2, wherein the centrally arranged recess in the spindle has its wall converged inwardly.

5. A fuel valve as claimed in claim 2, wherein the centrally arranged recess in the spindle is conical.

6. A device as claimed in claim 2, wherein the annular valve face proper formed by 130 the end surface of the valve spindle outwardly is bounded by a conical shaped surface, which at the edge of the valve face proper forms an angle with the valve face, greater than 90. l

7 A device as claimed in claim 3, wherein the annular valve seat of the-seat plu outwardly is bounded by a conical shapes surface, which at the edge of the valve seat forms an angle with the valve seat greater than 90.

8. A device as claimed in claim 3, wherein the bearing area of the valve spindle and seat is at least half as great as the full cross sectional area of the valve spindle.

9. An improved fuel valve for internal combustion engines of the type operating with direct injection o f fuel, comprising a housing, a valve spindle movable longitudinally in said housing and provided on its inner annular end .face with a centrally arranged recess, a fixed member arranged at the end of the housing for cooperating with saidv valve spindle, a central fuel-passage in said member and said fixed member having a recess corresponding to and coacting with the recess of the valve s indle, the diameter of said recess in said substantially greater than the diameter of the central fuelassa e.

In testimony w ereo I aiiix m signature.

. OVE PE ERSEN.

ed member being 

